This invention relates generally to prefabricated, structural framing members used in a broad range of construction applications and, more particularly, to a lintel having a metal side plate.
Lintels are typically used as structural framing members over windows and doors, as girders to support roof and floor trusses, and in other residential, industrial, commercial and agricultural applications. Generally, lintels span the distance between two spaced supports and carry structural loads, e.g., the weight of the structure above the lintel.
Known lintels are frequently fabricated on-site from two pieces of nominal xe2x80x9c2xc3x97Nxe2x80x9d lumber, e.g., 2xc3x9710 or 2xc3x9712 lumber (hereinafter referred to as xe2x80x9cchordsxe2x80x9d), and one or more pieces of filler material, e.g., xc2xdxe2x80x3 thick plywood, of selected lengths for the particular application. The filler material is sandwiched between the chords, and then nails are driven through the chords and the filler material to form a composite structural member. The filler material is usually required so that the actual thickness of the composite lintel matches the width of the framing members which support the lintel.
These known composite lintels generally have far more capacity and utilize far more materials than necessary for most applications in which they are used. Furthermore, being solid, site-built members, such lintels are time-consuming to make, heavy to carry, and labor-intensive to install.
Another known type of lintel is made partly of wood and partly of steel, and is marketed under the tradename Trifold. The known Trifold lintel includes a xe2x80x9c]xe2x80x9d shaped steel member having a center web portion, and integral flanges that extend in the same direction from opposing side edges of the web portion. To build a Trifold lintel, a wooden frame of desired size is constructed, and the steel member web portion is nailed or screwed to, and completely covers, one side of the wooden frame. One integral flange of the steel member extends over the top surface of the wood frame, and the other flange extends over the bottom surface of the frame. The Trifold lintel can then be installed, for example, over a window or door.
Although the Trifold lintel is lighter and utilizes less unnecessary materials than the composite lintels discussed above, like such composite lintels, the Trifold lintel is time-consuming and labor-intensive to assemble because of the large number of individually driven nails or screws that normally must be used to allow the Trifold lintel to carry common roof, floor or girder loads. Further, because the web portion covers the entire side of the wooden frame upon which it is installed, it substantially impedes the application of siding and other materials to that side of the lintel.
It would be desirable to provide a lintel which does not have significant unnecessary capacity and, therefore, wastes less materials than known composite lintels. It would be desirable to provide a lintel which may be pre-fabricated in a factory for delivery to a job site to eliminate the time, expense and imprecision associated with on-site assembly. It also would be desirable to provide a lintel which is relatively light weight to reduce shipping costs to the job site and to facilitate on-site handling, and to provide a lintel to which siding materials can be readily nailed or screwed without predrilling.
These and other objects may be attained by a lintel having a metal side plate in accordance with the present invention. The metal side plate provides many advantages including that waste is substantially reduced by eliminating unnecessary extra capacity, and such side plate enables pre-fabrication of the lintel in a factory for delivery to a job site. Use of the metal side plate also results in a relatively light weight lintel, which reduces shipping costs to the job site and facilitates on-site handling. In addition, with each of the embodiments of the subject lintel, siding materials can be readily nailed or screwed to the same side of the lintel to which the metal side plate is attached, without predrilling.
More particularly, and in an exemplary embodiment, a lintel constructed in accordance with the present invention includes a generally rectangular wood frame of a height, length and thickness substantially corresponding to the dimensions of the opening in which the lintel is to be installed. The frame is formed by connected first and second elongate chord members (e.g., nominal xe2x80x9c2xc3x97Nxe2x80x9d members) that extend in spaced, substantially parallel, overlying relationship to each other.
The subject lintel also includes at least one generally rectangular metal side plate having at least first and second spaced groupings of integrally formed teeth extending from one side along opposite longitudinal edges thereof. The first and second teeth groupings respectively engage the first and second chords. The metal side plate member has a width intermediate of the height of the frame and the distance between the first and second chords, and is positioned so as to overlap portions of coplanar side surfaces of the first and second chords on one side of the frame, while leaving a sufficient portion of one of the coplanar side surfaces exposed between its lower longitudinal edge and the bottom edge of the frame, to permit convenient fastener attachment of siding or other materials.
Many alternate embodiments of the subject lintel are contemplated, and several are specifically disclosed. For example, in one alternate embodiment generally intended for applications where the subject lintel may be required to carry heavier loads, the frame is provided with one or more internal stiffening members that are connected to and extend transversely between the first and second elongate chords. With this embodiment, the metal side plate may also be fabricated to include a third grouping of integral teeth spaced intermediate of the first and second groupings of teeth for engagement with the stiffening members.
In yet another embodiment of the subject lintel, a plurality of metal side plates are provided at predetermined locations spaced lengthwise along at least one side of the lintel frame to provide openings through which electrical, plumbing or other members may be conveniently passed without the need for drilling or cutting the subject lintel. In addition, for applications where the subject lintel may be required to carry extreme loads, metal side plates may be installed on both inner and outer sides of the lintel frame.
The subject lintel is a structural component capable of carrying substantial loads which minimizes unnecessary materials, production costs and waste. The lintel also lends itself to being prefabricated under factory conditions to reduce assembly costs, and may be made with a generally hollow inner core to reduce shipping costs. The hollow inner core also makes the lintel relatively light weight and easy to handle on-site. Optionally, the hollow inner core may be filled, preferably with a light weight material, to provide enhanced thermal or sound insulation performance. In addition, and in each of the various embodiments of the subject lintel described above, a portion of the lintel frame underlying the metal side plate is exposed, enabling convenient attachment of siding or other materials to the lintel.